Halogenated cyclic compounds are useful for example as intermediates for the preparation of various herbicides, insecticides, miticides, pesticides etc. U.S. patent application US 2006/0128702 A1 describes the synthesis of 3-trifluoromethyl-1H-Pyrazole (TFPZO) by reacting 4-ethoxy-1,1,1-trifluoro-3-buten-2-one with hydrazine dihydrochloride. Atherton and Fields, J. Chem. Soc. (C), 1968, p.1507-1513 describe the synthesis of 3-trifluoromethyl-1H-Pyrazole from 2,2,2-trifluorodiazoethane. The TFPZO compound is used as intermediate in chemical synthesis. European patent application EP-A-163280 discloses the manufacture of 2-hydroxy-4-trifluoromethyl pyrimidine (TFPMO) from the reaction product of TFAH with EVE. The TFPMO compound is used as intermediate in chemical synthesis, to produce pyrimidinylphosphates as pesticides.